Field of the Disclosure
The present disclosure, for example, relates to wireless communication systems, and more particularly to techniques for reserving a channel of a radio frequency spectrum.
Description of Related Art
Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, single-carrier frequency-division multiple access (SC-FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems.
By way of example, a wireless multiple-access communication system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, otherwise known as user equipments (UEs). A base station may communicate with UEs on downlink channels (e.g., for transmissions from a base station to a UE) and uplink channels (e.g., for transmissions from a UE to a base station).
Some modes of communication may enable communication between a base station and a UE over a shared radio frequency spectrum, or over different radio frequency spectrums (e.g., a dedicated radio frequency spectrum and a shared radio frequency spectrum) of a cellular network. With increasing data traffic in cellular networks that use a dedicated (e.g., licensed) radio frequency spectrum, offloading of at least some data traffic to a shared radio frequency spectrum may provide a cellular operator with opportunities for enhanced data transmission capacity. A shared radio frequency spectrum may also provide service in areas where access to a dedicated radio frequency spectrum is unavailable.
Prior to gaining access to and communicating over a shared radio frequency spectrum, a base station or UE may perform a listen before talk (LBT) procedure to contend for access to the shared radio frequency spectrum. An LBT procedure may include performing a clear channel assessment (CCA) procedure to determine whether a channel of the shared radio frequency spectrum is available. When it is determined that the channel of the shared radio frequency spectrum is available, a channel usage beacon signal (CUBS) may be transmitted to reserve the channel. When a potential transmitter on the first channel receives the CUBS and determines that an energy of the CUBS satisfies a threshold, the potential transmitter may refrain from transmitting on the first channel for a period of time. However, other potential transmitters on the first channel may determine that the energy of the CUBS does not satisfy a threshold, or may not receive the CUBS. These other potential transmitters may thus use the channel, or one or more interfering channels (e.g., an overlapping or adjacent channel), in a manner that interferes with the base station's or UE's reservation and use of the channel.